Issue with categories

Good morning

I have a problem with Flipbook categories.
Categories are not recognized (unlike other categories on my site) when I want to use a category when displaying a page, for example with “recent posts”
Indeed, I don’t want to display all the flipbooks at once, but for example 4 by 4

Thanks in advance

• This topic was modified 1 month, 2 weeks ago by jmfouquer.

The page I need help with: [log in to see the link]